This invention relates to a fluidized bed heat exchanger system and, more particularly, to an improved system for controlling the fluidized bed to rapidly respond to changes in demand in heat output from the fluidized bed.
The use of fluidized beds has long been recognized as an attractive means for generating heat. In the fluidized bed, air is passed through a bed of particulate material which includes a mixture of fuel material, such as high sulfer bituminous coal and an absorbent material, such as limestone, for the sulfur released as a result of the combustion of the coal. As a result of the air passing through the bed of particulate material, the bed is fluidized, which promotes combustion of the fuel. The basic advantages of the fluidized bed include a relatively high heat transfer rate, combustion at low temperatures, ease of handling of fuel waste materials, a reduction of corrosion and boiler fouling, and a reduction in boiler size.